(cba:news) august stars

Joe Patterson jop at astro.columbia.edu
Thu Jul 30 09:01:50 EDT 2020

Hi CBAers,

1. In recent years we've been accumulating a lot of data on "old novae", 
including some that are not so old, plus otherl which are related to old 
novae (which could be suspects from the pre-temescopic age, or which 
probably burn hydrogen stably rather than explosively).  It's time to 
bring some of these studies to print... and therefore to get a good 
final season, the better to nail down - typically - the orbital waveform 
and period change.

These are NR TrA, V4743 Sgr, Nova Sco 1437, V Sge (bright!), V617 Sgr, 
and QR And.  All new objects for this season, but friends of ours from 
past years.  None are *fast* variables, so you can just pick a time 
resolution you're comfortable with.  Howeve, since the period of 
interest is ORBITAL, the observation should be long (at least 3 hours)

V1494 Aql and V1974 Cyg are entitled to be on this list.  But V1494 has 
been well taken care of this year, and the signal in V1974 is hard to 
spot.  So I'm taking them off.

2. Intermediate polars (DQ Her stars).  Right up our alley to measure 
period change, since we have baselines of 5-20 years.  The ones needing 
just occasional observation are FQ Aqr and AO Psc.  V1223 is more 
interesting since it has been much more active this year, and a 
still-unsettled question is the connection between brightness and period 
change.  It will take some patience to settle this.

Then there are IPs that we have observed frequentlybut never quite 
published our results.  A good season on these will push us to 
completion!  These are V515 And, V1033 Cas, V2069 Cyg*, V2306 Cyg*, and 
V598 Peg.  The asterisk here means "we have a lot this year, but should 
take it to the end of the observing season, in order to secure a correct 
cycle count from one year to the next (or the previous).".

3. The asynchronous polars.  The good ones this season are CD Ind and 
V1432 Aql.  Need longish runs.

4. It's usually a good idea to find a good target, well placed in the 
sky, and stick with it.  But that's less true for the IPs, where early- 
and late-season observations can be critical in specifically long-term 
cycle count.

   I have at least the next semester off from teaching, and expect to 
bring a number of these studies to completion!

joe p

p.s. don't overlook N Sco 1437 - A really spectacular light curve! 
haven't made its acquaintance, A spectacular light curve
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